The aim of this study was to validate a French version (FMEQ) of the morningness-eveningness questionnaire (MEQ). Study 1 consisted of a translation by experts and an evaluation. The FMEQ and MEQ were proposed to 19 bilingual participants (age = 38.7 ± 13.7 years). Strong correlations between MEQ and FMEQ were obtained for most items. Study 2 tested the factorial structure and reliability of the FMEQ on a sample of 187 participants (20.46 ± 1.31 years). The confirmatory factor analysis indicated that the model had a good fit (χ2/df = 1.8; SRMR = 0.057) and a good reliability (Cronbach's alphas = 0.8). Concerning the temporal stability (20 participants: 20.48 ± 1.04 years), the Pearson r correlation coefficient for test-retest reliability was 0.87 (p < 0.001). Study 3 examined the predictive validity with 42 participants (19.52 ± 2.08 years). The global score of the FMEQ was significantly correlated with the time of peak temperature, wake-up time and bedtime. We did not observe superiority of a three-factors solution of the FMEQ. From now on, French subjects chronotype could be rigorously scored, and results from MEQ and FMEQ could be compared.
Keywords: Chronotype; circadian rhythms; diurnal preference; factor analysis; transcultural validation.